Foiled
by skrblr
Summary: Lavi and Allen return from a mission late one night. Allen has found a mysterious piece of paper, and asks Lavi what it means. And thus comes about Allen's ultimate mathematical enlightenment!


_Hi! Although this is based on an actual event, this still shouldn't seem too much like an inside joke. Or at least, if it does, you'll be on the inside, too. :) Tell me what you think!_

- - - - - - - - - - - - - - - - - - -

The scarlet puddle of tomato sauce pooled on Lavi's plate. Allen was bent over his penultimate dish of spaghetti, and Lavi was staring in awe at the remains of his past twenty pasta victims. Otherwise, the cafeteria was devoid of life, it being three in the morning and most of the other Headquarters employees being either asleep or slaving over research in the Science Department.

"All done!" Allen said proudly a few seconds later.

"Great! Bedtime!" said Lavi. "I hate missions where we get back late…"

"Oh, wait," Allen said. "I picked up this paper on the train, and I was wondering if maybe you knew what it meant." He pulled a neatly folded square from his pocket and handed it to Lavi. His eye widened.

"Nooooooo! FOIL!!!!!!" Allen scooted away a little at Lavi's agonized shriek. Hammer-boy recovered quickly, though. "Okay. Allen, by the time I am done teaching you this horrendous, despicable technique, you will be a mathematical guru like unto Pythagoras." Allen tipped his head, white hair flopping.

"Oh. Thank you very much!" He smiled, and Lavi bared his teeth in a sadistic grin.

"Yup. This'll be lots of fun."

He twirled one of his chopsticks and scribbled the paper's equation into his tomato sauce.

"X squared minus x minus 6 equals 0," Lavi muttered as he wrote. "Ready?" Allen nodded and swallowed a yawn. "'Kay. Since this is Foil, we start with two sets of parentheses, right next to each other." The chopstick drew four little arcs. "The 'F' in FOIL stands for first, or front, or something that starts with f. So, that's the first number or variable in either set of parentheses, and it's supposed to equal the first number in the initial equation. Beansprout, what times what is x squared?"

Blank stare.

Lavi's single green eye stared back for a second, then closed.

"Wonderful. How much basic algebra do you know?"

Blank stare.

Lavi came very close to cardiac arrest.

"Allennnnnn –"

"X times x," Allen suddenly said. "Sorry." Lavi started breathing again.

"And since it's MINUS 6, you can't have two positives because…" And Lavi explained the nature of multiplication and the evolution of arithmetic since the inception of the abacus.

"And that's why you have to multiply a negative times a positive," he concluded happily. Allen suddenly jerked awake.

"Ah, I see," he said.

"So, what are our possibilities to give us 6?"

"One six two three," Allen spouted off.

"Good! So, now to get the x right there – " Lavi's chopstick stabbed the x at the top of his plate – "We need to do the outside times the inside. The "oi" in FOIL, ya know. Outside? Inside? Yah?"

"Ah, I see."

"So, x times what plus x times what makes negative x?"

Allen smiled.

Lavi nodded encouragingly.

Allen kept smiling.

Lavi's own smile started wavering just a tiny bit.

Allen's didn't.

"Negative x…" Lavi prompted.

"Are you sure it's not negative six?" Allen asked.

"Ahahahahahahaha! Negative six! Ah, negative six… Mongolia… Good times, good times. And that yak tongue… Negative six… Heh." Lavi was quivering with laughter. Until, quite abruptly, he stopped.

"We just did that, remember? One six two three? The 'L' part of FOIL? 'L' for last?"

"Ah, I see."

"So, negative x, Beansprout."

Allen appeared to be too befuddled to respond to the loathed nickname. Lavi noticed, and he sat up straighter.

"All right. Here we go," he declared. "Pay close attention!" Allen leaned in, pleased that he didn't have to answer any more math questions yet.

"We multiply this x – " Lavi's chopstick touched the first x in the first set of parentheses – "by this, whatever number it turns out to be." The chopstick swooped across the tomato sauce to the very last space before the end of the second set of parentheses. "Then we multiply the other x by the last number in the first parentheses." The chopstick swooped again.

Allen squinted at the equation. Lavi, too, admired it, gazing at his handiwork proudly. Allen gasped.

"Hey! It looks like a dead smiley!" Lavi's eyebrow twitched disdainfully.

"Actually, as a matter of fact, it bears greater similitude to a reversed rainbow. Oh! And look!" Lavi doodled something in the left corner of the dish. "It's a unicorn!"

"Looks more like a camel to me." Lavi's one green eye grew dark with malice.

"It is a unicorn."

"Mm."

"Oh! Wait!" Lavi swiped a few more strokes with his chopstick. "Now the rainbow is a mouth! Oh! It looks like the Earl! Scary…."

---

In a distant undisclosed location, the Earl sneezed.

"Bless you," Road said.

---

"Anyway," Lavi said, back stiffening again, "You know it has to equal negative x, so it has to be – "

"Two and three," Allen proclaimed.

"Yeah, but which is negative?"

"Ummmm…"

Lavi dashed out some tiny numbers under the rest of the work. "See here? 2x and negative 3x is the only way to get negative 1x, which is the same as saying negative x… orcist!"

Allen blinked. "What?"

"Exorcist! X! X! Exorcist! And it's a negative exorcist…" Lavi made another small drawing in the bottom right corner. "See? Like Yuu! Cuz he's an exorcist, and he's always so negative. Negative x! Negative exorcist!"

"Kanda?" Allen said, brow furrowed and brain not grasping any of what Lavi just said.

"Yeah! So anyway, now you know that it's (x+2) and (x-3), and then you're done!" Lavi leaped onto the table, awaiting applause. Allen blearily looked up at him.

"Ta-da!" Lavi added, flourishing his chopstick.

"It's 4:30 in the morning," Allen said. "And I only slept a few hours on the train. And you didn't sleep at all, did you?"

"But now you know FOIL! What is sleep when pitted against the truest form of modern mathematics? The weariness of the body shall ever be overcome by the pursuit of knowledge!"

Allen glanced at the spaghetti plate. The equation was gracefully presented at the top, the unicorn on the left, the Millennium Earl's creepy grin in the middle, and the Negative eXorcist Kanda on the right.

"I'm going to bed."


End file.
